Rush Testing Kinder, Gentler Therapy for Lung Cancer

CHICAGO — Oncologists at Rush-Presbyterian-St. Luke’s Medical Center have begun testing a new medication that seeks to improve lung cancer treatment, reduce chemotherapy’s common side effects and decrease infusion time from one hour to about 15 minutes.

The medication being studied is called Xyotax, which links paclitaxel, a commonly used chemotherapuetic agent, to a biogradeable polymer. This polymer creates a new chemical, designed to deliver higher and potentially more effective levels of paclitaxel to tumors.

Paclitaxel is one of the families of chemotherapy agents known as taxanes, the most widely used anticancer drugs in the treatment of non-small cell lung, breast, ovarian, and prostate cancers. Patients with non-small cell lung cancer who qualify for this Phase III study will receive either Xyotax, or another therapy called docetaxel.

“It is a kinder, gentler treatment for lung cancer,” said Dr. Philip Bonomi, director of the Rush section of Oncology and Hematology and the only Chicago investigator in this study. “Xyotax offers patients convenience, shorter time spent in doctors’ offices, and I believe it will be less toxic.”

Unlike blood vessels in healthy tissue, those in tumor tissues have openings that make them porous to large molecules. Xyotax flows through healthy blood vessels and because the chemotherapy is inactive when bound to the polymer, lower levels of the drug are seen in the bloodstream. However, in tumor blood vessels, Xyotax leaks through the pores and is trapped in tumor tissue.

Xyotax is taken up by tumor cells through a process called pinocytosis. Because the polymer is made up of biodigestible amino acids, it is metabolized inside the tumor, releasing the paclitexal.

This allows Xyotax to bypass a primary mechanism by which tumor cells grow resistant. The result is that Xyotax should work better and be potentially safer than many existing chemotherapy agents.

Bonomi said that because this is a Phase III study, it is unclear just how well patients who take Xyotax will do. Bonomi believes that even if this drug shows a small improvement, the decreased side effects — nausea, hair loss and fatigue — it still might make Xyotax an attractive alternative to other chemotherapy agents if it gets Food and Drug Administration approval for widespread use.

Lung cancer is the leading cancer killer in both men and women. There were an estimated 156,900 deaths from lung cancer in the United States in 2000 and non small cell lung cancer deaths account for 85 percent of the 164,000 news cases of lung cancer that develop each year.